Let somebody else write only allistic characters. You can write a character who is probably, or maybe, on the spectrum, but this does not need a huge reveal or internal struggle—it can just be a thing you do, among other things you do, as an author.

The way you feel isn't a rational response to a defined situation, and can't be evaluated on that basis. Feelings don't stay contained and orderly. Some of your feelings may not even be about your writing.

Draw on the best of the way the world is and has been, as well as your most optimistic hopes for what it could be. The real world is very unfair to those on the margins. Use your writing to make up for it.